Anyone still even remotely interested in that house in Amityville, N.Y., or the people who lived in it for a few weeks 37 years ago needs an exorcism. That is way too long to be dwelling on a cheesy ghost story.

But such people no doubt exist, and they will probably seek out “My Amityville Horror,” a documentary by Eric Walter about Daniel Lutz, who was a child in the family at the center of the 1979 movie “The Amityville Horror.” Now in his mid-40s, Mr. Lutz prattles on endlessly about the paranormal activity he says he witnessed, the unpleasant family dynamics he grew up with and more.

Mr. Walter never makes this hostile, often vulgar man detail what he’s been up to since the 1970s or otherwise lets us get to know him. The film isn’t particularly interested in testing Mr. Lutz’s credibility so much as creating a psychological portrait of someone who may still be in the grip of real or imagined childhood trauma. But that would have taken more effort and nuance than went into this film. These days, when paranormal-themed shows are all over television, Mr. Lutz sounds like just another guy peddling an unverifiable spooky story.